I created a simple qml application to display Chinese/Japanese/Korean characters and made a snap package with ubuntu-app-platform plugin connected. I can see the same problem.
I suppose that it'd be best to fix this issue on ubuntu-app-platform so that we don't need to modify snapcraft.yaml file for each apps. Meanwhile it will not make any difference to package size as well since it will be a significant increase on package size if CJK font is snapped in each app.
I created a simple qml application to display Chinese/ Japanese/ Korean characters and made a snap package with ubuntu-app-platform plugin connected. I can see the same problem.
I suppose that it'd be best to fix this issue on ubuntu-app-platform so that we don't need to modify snapcraft.yaml file for each apps. Meanwhile it will not make any difference to package size as well since it will be a significant increase on package size if CJK font is snapped in each app.
Enclosed please find the screenshot.